It is not unknown to supply gasoline in both its liquid and vapor phases to a carburetor as shown, for example, in Pantano U.S. Pat. No. 2,882,882 wherein gasoline in its liquid phase is piped from the carburetor into a vaporizing chamber and the vapor produced in the vaporizing chamber is piped to the throat of the carburetor. Additionally, gasoline in its liquid phase is piped directly from the float chamber to the throat of the carburetor. A somewhat similar system is shown in Thomas U.S. Pat. No. 2,315,881 wherein gasoline in its liquid phase is heated within a jacketed tank to generate a vapor at the top of the tank and gasoline in its liquid phase and its vapor phase are withdrawn from the bottom and top, respectively, of the tank and delivered, respectively, to the float chamber of the carburetor and to the throat of the carburetor. The system shown in the Thomas patent requires specialized carburetors. In Hirschler U.S. Pat. No. 3,783,841, gasoline is vaporized within a vaporizing tank, gasoline in its liquid phase is drawn off from the bottom of the tank and gasoline in its vaporized form is drawn off at the top of the tank. The gasoline in its vaporized form is condensed thereto, combined with the liquid gasoline and delivered to the carburetor. The system shown in the Hirschler patent functions only during the period of warm-up of the engine to operating temperature, at which time it shuts off and the fuel system reverts to normal operation. The Hirschler system was designed only to control emission during the rich mixture supplied while the engine is cold. A similar system is shown in Ryan U.S. Pat. No. 2,645,906. A system in which gasoline is converted entirely to its vaporized phase for delivery to the carburetor is shown in Chapin U.S. Pat. No. 1,530,882. The systems shown in Ryan and Chapin are prone to vapor lock. The system of the present invention is designed to be operated with standard carburetors without alternation of the latter; to be operative during normal driving conditions as contrasted to warm-up; to minimize pollution; and to be free from vapor lock.